Analyses of biological and chemical specimens may be performed conventionally using large, expensive laboratory equipment requiring skilled scientists trained to operate the equipment and interpret the results. Specimens may analyzed to determine the presence of one or more analytes within the specimen, e.g., a pathogen or virus, a particular chemical, and antigen or antibody, etc, for medical purposes. In some cases, bioassays are performed by tagging a sample with a fluorescent tag that emit light of a particular wavelength. The tag may be illuminated with an excitation light source to cause fluorescence. The fluorescence is detected with a photodetector, and the signal analyzed to determine a property about the sample. Bioassays using fluorescent tags conventionally involve expensive laser light sources and optics arranged to illuminate samples. The assays may further involve bulky, expensive collection optics arranged to collect the fluorescence from the samples as well as expensive electronic instrumentation to process the signals.
Because conventional analytical equipment is typically expensive and requires a skilled operator, specimens to be analyzed may need to be sent to an on-site or off-site facility for processing. This can introduce appreciable delay and cost associated with even routine analysis of a specimen. For example, a patient may have to wait several days and schedule a return visit to a doctor's office to learn about the results of a laboratory test on a specimen provided by the patient.